Sewing machine for attaching bindings on the edges of fabrics by means of chainstitch seams blind on one side of the binding



Nov. 4. 1969 N. MARFORIO 3,476,065

SEWING MACHINE FOR ATTACHING BINDINGS ON THE EDGES OF FABRICS BY MEANS OF CHAINSTITCH SEAMS BLIND ON ONE SIDE OF THE BINDING Filed Jan. 16, 1967 A 8 Sheets-Sheet 1 NERIN O mHRFORIo e MQMMMMM M Nov. 4. 1969 N. MARFORIO 3,476,065 SEWING MACHINE FOR ATTACHING BINDINGS ON THE EDGES OF FABRICS BY MEANS OF CHAINS-'I'I'ICH SEAMS BLIND ON ONE SIDE THE BINDING OF Filed Jan. 16, 1967 8 Sheets-Sheet 2 Nov. 4. 1969 N. MARFORIO 3,476,065

SEWING MACHINE FOR ATTACHING BINDINGS ON THE EDGES OF FABRICS BY MEANS O CHAINSTITCH SEAMS BLIND on om; SIDE OF THE BINDING Filed Jan. 16, 1967 8 Sheets-Sheet 3 NOV. 4. 1969 M R omo 3,476,065

SEWING MACHINE FOR ATTACHING BINDINGS ON THE EDGES OF FABRICS BY MEANS OF CHAINSTITGH SEAMS BLIND ON ONE SIDE OF THE BINDING Filed Jan. 16. 1967 8 Sheets-Sheet 4 Nov. 4. 1969 MARFORIO 76,065 SEWING MA NE ATT ING BINDINGS ON THE ES 0 BRICS ME 0F CHAINSTITCH SEAMS BLIND ONE SIDE OF THE BINDING Filed Jan. 16, 1967 8 Sheets-Sheet 5 NOV. 4. 1969 ARFORIO 3,476,065

SEWING MACHINE FOR ATT BINDINGS ON THE EDGES OF FABRICS BY MEANS OF CHAINSTITCH AMS BLIND ON ONE SIDE QFTHE NDING Filed Jan. 16, 1967 8 Sheets-Sheet 6 WING MACH N v NE FOR RF BY MEANS gg agg NDlfiz gON THE 3,476 0 S195; STITCH SEAMS BLIN EDGES OF FABRI,(;5 OF E BINDING D N ONE Filed Jan. 16, 1967 8 Sheets Sh eat 7 SEWING MACHI N MA NE F0 F'OR BY MEN? 3;" ggfggg f ggm'f ON THE EDGES 3 5 6,065 SEA BR Flled Jan. 1 1967 IDE OF THE BINS I N ON ONE ms 8 Sheets-Sheet 8 United States Patent 3,476,065 SEWING MACHINE FOR AITACHING BINDINGS ON THE EDGES 0F FABRICS BY MEANS OF CHAINSTITCH SEAMS BLIND ON ONE SIDE OF THE BINDING Nerino Marforio, Milan, Italy, assignor to S.p.A. Virginio Rimoldi & C., Milan, Italy Filed Jan. 16, 1967, Ser. N0. 609,643 Claims priority, application Italy, Feb. 12, 1966, 32,225/ 66 Int. Cl. D051) 1/06, 85/02; A41h 31/00 U.S. Cl. 112-197 4 Claims ABSTRACT OF THE DISCLOSURE A sewing machine for sewing a binding along the edge of a fabric with a chainstitch in a manner whereby the stitch is blind on one side of the binding, comprising a sewing needle whose point is radially displaced from the needle axis and a thread guide groove whose plane of symmetry is displaced relative to the line along which stitches are formed in the binding and fabric.

This invention relates to a sewing machine for attaching bindings on the edges of fabrics by means of chainstitch seams blind on one side of the binding.

The finishing of the edges of fabrics, in particular of knitted fabrics, by attaching to the edges the bindings which are obtained by means of folding a strip of knitted or other fabric, so as to give to the strip in cross section a U-shaped, the marginal parts of which are folded inside of the U-shape, is already known. Said strip, while passing during its feeding, through a suitable guide or folder, is lapped around the edge of fabric and is attached to it by means of lock stitches.

In order to get this result, lock stitch sewing machines have been used, which are provided with suitable guides for effecting the desired folding of binding, during its passage through said guide, and which is suitably set in respect to the feeding direction and to the work plate of the machine, in order to permit the penetration of the needle into the thickness of the marginal part which is folded at the inside of the U-shape of the binding, immediately before this part is overlapped to the upper part of the fabric edge.

The lock stitch sewing machines are designed for the above-mentioned operation owing to the particular arrangement of the looper, with which they are provided, which is travelling in a plane parallel to the feeding direction and therefore can easily seize the loop of the needle thread which is formed at one side of the plane perpendicular to the throat plate and containing the line of the seam.

It has been noticed, however, that the use of the lock stitch sewing machines is not convenient when they have to finish the fabric edges by attaching to them the knitted bindings which are cut on the bias, giving them the maximum stretchiness, as required in knitted outerwear manufacturing and when the maximum elasticity, not only of the fabric, but also of the seams is required. In fact, it is known that the lock stitch seams have not enough elasticity to allow their use in the seams of knitted outerwear garments.

The sewing machines using the lock stitch present a further trouble, due to the fact that it is necessary to replace very often the bobbin, which contains a limited length of looper thread, that requires several replenishing operations, consequently losing time and increasing production costs. The main reason in not using the chainstitch sewing machines for attaching U-folded bindings "ice to the edges of fabrics by blind seams, is that the part of the needle thread which is disposed between the needle eye and the fabric, and more precisely between the eye and the latter previously made stitch, runs sideways in respect to the direction of seam formation. This determines the formation of a loose-stitch seam and causes missed stitches during the seam formation, due to the missed seizing of the needle thread loop by the looper during the upwards stroke of the needle; said looper travelling in the chainstitch sewing machine types, as is known, is a plane which is oriented transversally in respect to the direction of seam formation. There is also the trouble of the needle thread breakage due to the particular disposition of the fabric on the machine in cooperation with the needle point lying aligned with said needle thread, so that the latter can be touched easily by the needle point before the needle is penetrating into the fabric during each downwards stroke.

According to this invention these troubles are avoided by the fact that the machine is provided with means for the chainstitch formation, preferably double chainstitch, and is also provided with a needle the point of which is displaced in respect to the symmetrical main axis of the needle and in which the short thread groove guiding the thread between the needle eye and the latter made stitch, is made in such a position that its symmetrical plane is inclined in respect to the plane in which the seam is formed and in respect to the plane containing said needle point, when the needle is mounted on the machine.

Other features and advantages of the invention will become apparent from the description which follows, of a preferred embodiment thereof, given by way of example only, and in which reference will be made to the accompanying drawings, in which:

FIGURE 1 is a side elevation of a chainstitch sewing machine;

FIGURE 2 is an enlarged front elevation of same;

FIGURE 3 is a fragmentary plan view of the workplate, of the presser foot and of the folder;

FIGURE 4 is a fragmentary perspective view of said machine on which there are the fabric and the binding which has been attached to the edge of said fabric;

FIGURE 5 is a side elevation of the needle;

FIGURES 6, 7, 8 and 9 are sections substantially taken along the lines VI-VI, VII-VII, VIIIVIII, IXIX, of FIGURE 5;

FIGURE 10 is a front elevation of the presser foot;

FIGURES 11 and 12 are the side elevations and the relative views of same;

FIGURES 13, 14, 15 and 16 are fragmentary diagrammatic perspective views of the stitch formation;

FIGURE 17 is an enlarged fragmentary view of the stitch which has been formed into the fabric;

FIGURE 18 is a fragmentary side elevation of the needle.

The machine illustrated in the enclosed drawings, includes a base 1 the front of which is provided with a workplate 2. A needle 3 is carried, as known, on a sliding vertical bar 3a mounted in a head 4a of an arm 4 of the machine. Parallel to the needle 3 is placed a presser bar 5 carrying a presser foot 6. Under a throatplate 7 is placed a looper 8, in which is threaded a thread Fc, which is carried by known mechanisms in such a way that oscillations can be effected in planes substantially perpendicular to the direction of feeding, as also displacements in direction parallel to the vertical plane in which the seam is formed, as it is necessary, for the formation of the chainstitch, that the looper passes once before (looking in the direction of feeding) and once behind said needle. At the presser foot is fixed, by means of a support 9 and screws 10, a folder 11 for folding a binding 12 being supplied by a reel 13 which is freely mounted on a spindle 14 fixed to a table 15 supporting said machine. The work of the folder 11, the structure of which is per se known, is to fold the binding 12 in such a way as to shape it into a U, in cross section, the edges of which are folded within the U-shape. Said folder is placed so that it can supply the binding in a direction substantially perpendicular to the feeding direction of a fabric 16 (FIGURE 4). Said folder 11 is placed at a such a height that the top side of the U-section of folded binding at the end of its passage through the folder, is overlapped on to an edge 16a of the fabric 16, while the bottom side of above-mention U-section of the binding is placed between the edge 16a of the fabric and the throat-plate 7 (FIGURE 1). Besides, the plane of the folder is slightly inclined so that the marginal part which is folded within the top side of the U-section of the binding, assumes, in the place corresponding to where it is deviated in the same direction of feeding, a position substantially perpendicular to the throat-plate for making easier the penetration of the needle during its downwards stroke through the thickness of the fabric.

Owing to this conformation and disposition of said parts, the needle 3 passes through the thickness of the binding in correspondence to the position of this binding which is placed, after its overla ping on to the edge 16a of the fabric (FIGURE 4) between this edge and the top side of the U-section of the binding. In such a way the seam cannot be seen in correspondence to the side of the binding which has been overlapped on to the fabric 16, whilst it san be seen at the other side, that is corresponding to the side of the binding that is placed during the seam between the fabric 16 and the throatplate 7.

The needle 3, illustrated in detail in FIGURES to 8 of the drawings, comprises a shank 18 provided with a flat 19 at one side for allowing the correct inserting of said needle in the needle bar (not illustrated). The shank 18 is jointed by means of a bevelled part 20 with a blade 21 that ends with a point 22 on the top of which is needle eye 23. The point 22 is displaced in respect to a main axis 24 of the needle and is laced close to the perimeter 25 of the cross section of the blade 21 (FIGURES 6 and 7) in a plane PP forming an angle of about 45 with the plane YY parallel to the fiat 19, in which plane YY the seam is formed, when the needle is mounted on the machine.

Said point 22 is disposed at the side of said plane YY opposite to the edge of the fabric on which the binding is attached.

In the blade 21 there is a long thread groove 26 beginning in correspondence to the bevelled part 20 and communicating with the needle eye 23. Said groove is symmetrical in respect to said plane YY of the needle and guides the needle thread which is supplied by the spool (not illustrated), usually mounted on the supporting table 15.

At the diametrically opposite side of the needle and slightly beyond the needle eye 23, the blade 21 has a gap 27 for receiving the point 8a of the looper 8 (FIG- URE 13) in order to facilitate the seizing by this looper of the loop and of the needle thread Fa being formed during the upwards stroke of the needle.

A short, substantially straight thread groove 28 extends from the top of the gap 27 (FIGURES 5 to 9) within the blade 21 to the bevelled part 20; said groove 28 is enlarged close to said bevelled part 20 and is adapted so that its bisector plane LL is inclined in respect to the plane YY, and is substantially perpendicular to the plane PP.

The purpose of the displacement of the point 22 in respect to the main axis 24 of the needle is to meet the need to ensure the penetration of the needle into the binding without the needle touching the thread belonging to the previous stitch. The aim of the particular conformation of the short thread groove 28 is, in its turn, to guide the part of the thread interposed between the needle eye and the fabric of the binding during the needles downwards strokes for assuring the flowing of the thread and the regular locking of the previously made stitch, and for avoiding that the needle thread loop is deflected sideways in respect to the direction of feeding, just when the looper point 8a is seizing said loop.

The presser foot 6 is designed in order to facilitate the feeding and the flattening of the binding 12 folded like a U-shape, during and immediately after the stitch formation. Said presser foot is also designed in order to allow a very precise adjustment of the folder 11 (FIG- URE 3) which it supports in respect to the needle 3, in order to allow the adaption to the thickness of the binding fabric.

The presser foot 6 has a sliding plate 29 (FIGURES 10 to 12) on one side of which there are two threaded holes setting on it the support 9 (FIGURES 3 and 4) and on the other side of which an upstanding lug 32 is provided. Said lug 32 is provided with a through slot 33. In front of said lug there is a presserfoot toe 29a.

The upstanding lug 32 is slidingly mounted within a guiding groove 34 which is made in a side extension 35a of a bracket 35 which is used for setting the presser foot to the presser bar 5 (FIGURE 1) as described hereinafter.

The extension 3511 is provided with an elongated slot 36 within which a screw 37 is inserted, which is screwed into a hole (not illustrated) on the upstanding lug 32.

Obviously, acting on the screw 37 the upstanding lug 32 can be fixed against the bottom of the guiding groove 34 setting the presser foot toe 29a in respect to its bracket 35. The displacement of said toe 29a in respect to said guiding groove 35 can be controlled by the rotation of a threaded pin 38, a knurled hand-nut 39 of which is engaged in the through slot 33 of said lug 32, and which is screwed into a threaded hole which is made in the side extension 35a of the bracket 35, parallel to the guiding groove 34. The bracket 35 has also a vertical groove 40 which is provided for engaging the lower end of the presser bar 5 and in correspondence to the top of said bracket 35 there is an apertured groove 41 for a screw 42 (FIGURE 4) which is screwed in a threaded hole of the presser bar 5, said screw is provided for setting the bracket on said presser bar 5.

The binding 12 which is supplied by the reel 13 being freely mounted on the spindle 14 is fed through two braking elements which are pins 43 on each one of which an adjustable block 45 is inserted, which is fixed by a screw 44 and each block is provided with a pin 46. Orienting in the right way the pin 46 in respect to the relative pin 43, which can be obtained by turning the block 45, it is possible to create a braking effect on the binding 12 during its passing from the reel 13 to the folder 11.

In order to prepare the binding at the mouth of the folder 11, it has to pass through a previous forked guide 47 suitably inclined, fixed to the base of the machine by means of a screw 48.

What is claimed is:

1. A sewing machine for sewing a binding onto a fabric edge by means of a chainstitch which is blind on one side of the binding, said machine comprising a sewing needle having a longitudinal axis and an eye, a point, and a first longitudinally extending groove symmetrical with a first plane which includes said axis for guiding the needle thread, and a second longitudinally extending guide groove for guiding a sewing thread between said eye and a last precedingly formed stitch, the machine also comprising means cooperatively associated with said needle for forming a chainstitch in a fabric along a line of stitching which runs perpendicularly to said axis and in said first longitudinal plane, said needle point displaced radially from said axis and lies within a second longitudinal plane which includes said axis, said second groove being bisected by a third longitudinal plane which is angularly displaced relative to said first plane and is perpendicular to said second plane. Y

2. The sewing machine of claim 1, wherein said needle point, eye, and second groove are disposed along a blade portion of said needle, said blade portion having an outer periphery which is symmetrical relative to said axis as seen in a radial plane which is perpendicular to said axis, said point as seen in said radial plane being disposed along said second plane and proximate to said outer periphery, said second plane forming an angle of substantially 45 with said first plane, said needle and said means cooperatively associated therewith for forming a chainstitch in a fabric being arranged to sew said chainstitch along the edge of a fabric with the fabric-edge and said needle point being disposed on respective opposite sides of said first plane.

3. The sewing machine of claim 1, wherein said second and third planes form substantially equal angles with said first plane about said axis on respective opposite sides of said first plane.

4. The sewing machine of claim 1, wherein said needle comprises a shank portion, which is adapted to be gripped by a needle bar of the machine, and a blade portion extending longitudinally from said shank portion, said eye and said guide groove being disposed in longitudinal sequence along the extent of said blade, a gap being interposed between the top of said eye and the bottom end of said groove, said groove extending upwardly from the top of said gap towards said shank and said groove including an enlarged portion near to said shank, said groove being substantially straight.

References Cited UNITED STATES PATENTS 360,884 4/ 1887 Hutchinson 112-222 1,323,340 12/1919 Weis 112222 1,529,312 3/ 1925 Hughes l12140 X 1,756,036 4/1930 Seaman 1l2140 X 2,669,956 2/1954 Haines 112176 X 2,769,415 11/1956 Sigoda 112176 X 2,940,406 6/ 1960 Marforio 112-197 3,005,428 10/ 1961 Vorn Lehn 112- 222 3,134,347 5/1964 Seaman 112-176 X 3,191,560 6/1965 Marforio 112197 3,347,192 10/1967 Lukins 112-222 HERBERT F. ROSS, Primary Examiner U.S. Cl. X.R. 112-222; 223102 

